A 16-year-old youth seen fleeing the scene of a fatal shooting is now behind bars, charged with murder.

Manuel D. Lopes, 16, of 17 Kenwood St., Apt. 3, Brockton, was ordered held without bail Tuesday by Judge Paul J. McCallum after pleading innocent to charges of murder, carrying a dangerous weapon, unlawful possession of ammunition and discharge of a firearm within 500 feet of a dwelling.

Lopes is accused of killing Matthew Collins, 18, of Brockton, Monday evening on East Main Street.

A second man, Admir Lopes Resende, 19, of 589 North Montello St., Apt. 1, Brockton, is charged with accessory after the fact in the case. Resende, who also pleaded innocent Tuesday at his arraignment, was ordered held in lieu of $100,000.

Plymouth County District Attorney Timothy J. Cruz said police rushed to East Main Street after receiving a call about shots fired and found Collins, the victim, with a gunshot wound to the chest. Collins was taken to Good Samaritan Medical Center, where he later died.

Cruz said witnesses told police they saw a teenager fleeing the scene with a handgun.

According to paperwork filed in court, Lopes opened fire on a group of males running south on East Main Street by East Battles Street about 5:30 p.m. The two suspects then ran into Resende’s North Montello Street house, where they were caught.

After obtaining a search warrant, authorities recovered a .25-caliber firearm in a plastic bag in the backyard of the house, according to paperwork filed in court.

Lopes, the murder suspect, attended Brockton High School as a freshman for two years before he was reassigned to the B.B. Russell Alternative High School for this school year, said Susan Szachowicz, BHS principal.

He left the school at the beginning of this year, said Brockton School Department spokesman James Hayden.